Peter Mathews made a name for himself as a television commentator on the banking crisis, and was wooed by Fine Gael to run for the party in Dublin South in the 2011 election. At the age of 59, he was elected on his first attempt.

As a chartered accountant, Mathews had made much of his financial expertise to castigate the Cowen administration’s response to the banking debacle and the formation of Nama.

Once in the Dáil, he earned a reputation for criticising his own Government’s banking policy. What is more, fellow TDs found reason to bemoan his long-winded contributions to parliamentary party meetings.

Mathews annoyed Enda Kenny greatly last year by provoking a finance committee vote that the Government lost, leading to a 6.30am dressing down from the Taoiseach. Similarly, his entreaties at the same committee to Michael Noonan to seize the initiative in EU talks went down badly with the Minister for Finance.

“Do a Khrushchev on it and take your shoe off and bang it on the table,” Mathews urged Noonan, referring to a 1960 intervention at the UN by the then Soviet leader.

The Minister replied that rhetoric could sometimes work, but that the best results were achieved on the margins of meetings.

Abortion legislationFor all that, it was his stance on the abortion legislation that wrecked Mathews’s career with Fine Gael. Having campaigned unsuccessfully for a free vote on the matter, he lost the whip when he voted against the new law.

His decision to leave the party altogether comes soon after his alignment with other Fine Gael dissidents in the Reform Alliance.